Demonic (2015)

A violent slaughter occurs in an abandoned house in Louisiana where three college students are found dead. Detective Mark Lewis examines the crime scene and finds a shocked survivor, John, before calling reinforcements. Several police cars then arrive at the house alongside an ambulance with psychologist, Dr. Elizabeth Klein. She talks to John, who tells her that a séance performed in the house called the attention of many spirits, including one he identified as his mother, and that two of the group members – his pregnant girlfriend, Michelle, and her ex-boyfriend, Bryan – are still missing.

The following scenes consist of two interlaced plots: one shows the interrogation of John by Dr. Klein and the investigation of videotapes found in the house by police officers, and the other shows the actual events (often filmed by a camera) that John and the five other visitors of the house experienced, including several paranormal phenomena.

Bryan is later found alive but runs away from the police, ending up cornered in a store. John hears the news on the police radio and, in a fit of rage, grabs a radio, shouting at Bryan to tell him where Michelle is. Bryan begins to act strangely while John almost goes into cardiac arrest. Elizabeth screams for Mark to stop Bryan before he kills John, wherein Mark promptly shoots Bryan dead.

Mark returns to the house and discovers a secret area where he finds Michelle. As the paramedics are rolling her on the stretcher, Elizabeth discovers that John killed everybody at the same time that Detective Mark finds John's lifeless body hanging.

As it turns out, the "John" that Elizabeth was interrogating was a demon, who, as he begins to make Elizabeth choke, elaborates on the events that transpired – the seal the group found in the living room is what bound him to the house; John's mother was supposed to be the vessel of his escape, his possessing John, killing everybody and that he needs to cross the seal – in order to set himself free. The lights begin to turn on and off, and as Mark bursts open the door, the demon vanishes just as Michelle is wheeled out of the house.

The film concludes with Michelle in the ambulance showing a sinister figure moving in her belly.